In the vacuum casting of molten metals, such as superalloys, a superalloy charge is melted in a melting furnace vessel (e.g. crucible) in an upper melting chamber usually under vacuum and then poured into casting mold positioned in a lower mold pour chamber located beneath the melting chamber and communicated thereto via an open isolation valve. In many cases, the molten metal pour stream height from the melting vessel above the underlying refractory mold is reduced by raising the mold in the lower mold pour chamber using an elevator or other mold lift mechanism. However, in the case of fixed mold height equipment, the distance of the mold from the melting vessel results in an inherently long molten metal pour stream that is difficult to control and can introduce molten metal turbulence within the mold during mold filling.
An object of the present invention is provide a melt delivery system that substantially reduces the length of the melt pour stream from a melting vessel to a casting vessel, such as a mold or shot sleeve, and overcomes problems associated with the above described upper melting chamber/lower mold pour chamber system.